linux-stable.git/fs/proc, branch v5.10.78

proc: Avoid mixing integer types in mem_rw()

2021-07-28T12:35:42+00:00

[ Upstream commit d238692b4b9f2c36e35af4c6e6f6da36184aeb3e ]

Use size_t when capping the count argument received by mem_rw(). Since
count is size_t, using min_t(int, ...) can lead to a negative value
that will later be passed to access_remote_vm(), which can cause
unexpected behavior.

Since we are capping the value to at maximum PAGE_SIZE, the conversion
from size_t to int when passing it to access_remote_vm() as "len"
shouldn't be a problem.

Link: https://lkml.kernel.org/r/20210512125215.3348316-1-marcelo.cerri@canonical.com
Reviewed-by: David Disseldorp 
Signed-off-by: Thadeu Lima de Souza Cascardo 
Signed-off-by: Marcelo Henrique Cerri 
Cc: Alexey Dobriyan 
Cc: Souza Cascardo 
Cc: Christian Brauner 
Cc: Michel Lespinasse 
Cc: Helge Deller 
Cc: Oleg Nesterov 
Cc: Lorenzo Stoakes 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Sasha Levin

mm/huge_memory.c: add missing read-only THP checking in transparent_hugepage_enabled()

2021-07-14T14:56:50+00:00

[ Upstream commit e6be37b2e7bddfe0c76585ee7c7eee5acc8efeab ]

Since commit 99cb0dbd47a1 ("mm,thp: add read-only THP support for
(non-shmem) FS"), read-only THP file mapping is supported.  But it forgot
to add checking for it in transparent_hugepage_enabled().  To fix it, we
add checking for read-only THP file mapping and also introduce helper
transhuge_vma_enabled() to check whether thp is enabled for specified vma
to reduce duplicated code.  We rename transparent_hugepage_enabled to
transparent_hugepage_active to make the code easier to follow as suggested
by David Hildenbrand.

[linmiaohe@huawei.com: define transhuge_vma_enabled next to transhuge_vma_suitable]
  Link: https://lkml.kernel.org/r/20210514093007.4117906-1-linmiaohe@huawei.com

Link: https://lkml.kernel.org/r/20210511134857.1581273-4-linmiaohe@huawei.com
Fixes: 99cb0dbd47a1 ("mm,thp: add read-only THP support for (non-shmem) FS")
Signed-off-by: Miaohe Lin 
Reviewed-by: Yang Shi 
Cc: Alexey Dobriyan 
Cc: "Aneesh Kumar K . V" 
Cc: Anshuman Khandual 
Cc: David Hildenbrand 
Cc: Hugh Dickins 
Cc: Johannes Weiner 
Cc: Kirill A. Shutemov 
Cc: Matthew Wilcox 
Cc: Minchan Kim 
Cc: Ralph Campbell 
Cc: Rik van Riel 
Cc: Song Liu 
Cc: William Kucharski 
Cc: Zi Yan 
Cc: Mike Kravetz 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Sasha Levin

proc: only require mm_struct for writing

2021-06-16T10:01:47+00:00

commit 94f0b2d4a1d0c52035aef425da5e022bd2cb1c71 upstream.

Commit 591a22c14d3f ("proc: Track /proc/$pid/attr/ opener mm_struct") we
started using __mem_open() to track the mm_struct at open-time, so that
we could then check it for writes.

But that also ended up making the permission checks at open time much
stricter - and not just for writes, but for reads too.  And that in turn
caused a regression for at least Fedora 29, where NIC interfaces fail to
start when using NetworkManager.

Since only the write side wanted the mm_struct test, ignore any failures
by __mem_open() at open time, leaving reads unaffected.  The write()
time verification of the mm_struct pointer will then catch the failure
case because a NULL pointer will not match a valid 'current->mm'.

Link: https://lore.kernel.org/netdev/YMjTlp2FSJYvoyFa@unreal/
Fixes: 591a22c14d3f ("proc: Track /proc/$pid/attr/ opener mm_struct")
Reported-and-tested-by: Leon Romanovsky 
Cc: Kees Cook 
Cc: Christian Brauner 
Cc: Andrea Righi 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

proc: Track /proc/$pid/attr/ opener mm_struct

2021-06-16T10:01:34+00:00

commit 591a22c14d3f45cc38bd1931c593c221df2f1881 upstream.

Commit bfb819ea20ce ("proc: Check /proc/$pid/attr/ writes against file opener")
tried to make sure that there could not be a confusion between the opener of
a /proc/$pid/attr/ file and the writer. It used struct cred to make sure
the privileges didn't change. However, there were existing cases where a more
privileged thread was passing the opened fd to a differently privileged thread
(during container setup). Instead, use mm_struct to track whether the opener
and writer are still the same process. (This is what several other proc files
already do, though for different reasons.)

Reported-by: Christian Brauner 
Reported-by: Andrea Righi 
Tested-by: Andrea Righi 
Fixes: bfb819ea20ce ("proc: Check /proc/$pid/attr/ writes against file opener")
Cc: stable@vger.kernel.org
Signed-off-by: Kees Cook 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

proc: Check /proc/$pid/attr/ writes against file opener

2021-06-03T07:00:28+00:00

commit bfb819ea20ce8bbeeba17e1a6418bf8bda91fc28 upstream.

Fix another "confused deputy" weakness[1]. Writes to /proc/$pid/attr/
files need to check the opener credentials, since these fds do not
transition state across execve(). Without this, it is possible to
trick another process (which may have different credentials) to write
to its own /proc/$pid/attr/ files, leading to unexpected and possibly
exploitable behaviors.

[1] https://www.kernel.org/doc/html/latest/security/credentials.html?highlight=confused#open-file-credentials

Fixes: 1da177e4c3f41 ("Linux-2.6.12-rc2")
Cc: stable@vger.kernel.org
Signed-off-by: Kees Cook 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

fs/proc/generic.c: fix incorrect pde_is_permanent check

2021-05-19T08:13:09+00:00

[ Upstream commit f4bf74d82915708208bc9d0c9bd3f769f56bfbec ]

Currently the pde_is_permanent() check is being run on root multiple times
rather than on the next proc directory entry.  This looks like a
copy-paste error.  Fix this by replacing root with next.

Addresses-Coverity: ("Copy-paste error")
Link: https://lkml.kernel.org/r/20210318122633.14222-1-colin.king@canonical.com
Fixes: d919b33dafb3 ("proc: faster open/read/close with "permanent" files")
Signed-off-by: Colin Ian King 
Acked-by: Christian Brauner 
Reviewed-by: Alexey Dobriyan 
Cc: Greg Kroah-Hartman 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Sasha Levin

seccomp: Fix CONFIG tests for Seccomp_filters

2021-05-14T07:50:24+00:00

[ Upstream commit 64bdc0244054f7d4bb621c8b4455e292f4e421bc ]

Strictly speaking, seccomp filters are only used
when CONFIG_SECCOMP_FILTER.
This patch fixes the condition to enable "Seccomp_filters"
in /proc/$pid/status.

Signed-off-by: Kenta Tada 
Fixes: c818c03b661c ("seccomp: Report number of loaded filters in /proc/$pid/status")
Signed-off-by: Kees Cook 
Link: https://lore.kernel.org/r/OSBPR01MB26772D245E2CF4F26B76A989F5669@OSBPR01MB2677.jpnprd01.prod.outlook.com
Signed-off-by: Sasha Levin

proc: don't allow async path resolution of /proc/thread-self components

2021-03-04T10:38:42+00:00

commit 0d4370cfe36b7f1719123b621a4ec4d9c7a25f89 upstream.

If this is attempted by an io-wq kthread, then return -EOPNOTSUPP as we
don't currently support that. Once we can get task_pid_ptr() doing the
right thing, then this can go away again.

Use PF_IO_WORKER for this to speciically target the io_uring workers.
Modify the /proc/self/ check to use PF_IO_WORKER as well.

Cc: stable@vger.kernel.org
Fixes: 8d4c3e76e3be ("proc: don't allow async path resolution of /proc/self components")
Reported-by: Eric W. Biederman 
Signed-off-by: Jens Axboe 
Signed-off-by: Greg Kroah-Hartman

proc: use kvzalloc for our kernel buffer

2021-03-04T10:38:21+00:00

[ Upstream commit 4508943794efdd94171549c0bd52810e2f4ad9fe ]

Since

  sysctl: pass kernel pointers to ->proc_handler

we have been pre-allocating a buffer to copy the data from the proc
handlers into, and then copying that to userspace.  The problem is this
just blindly kzalloc()'s the buffer size passed in from the read, which in
the case of our 'cat' binary was 64kib.  Order-4 allocations are not
awesome, and since we can potentially allocate up to our maximum order, so
use kvzalloc for these buffers.

[willy@infradead.org: changelog tweaks]

Link: https://lkml.kernel.org/r/6345270a2c1160b89dd5e6715461f388176899d1.1612972413.git.josef@toxicpanda.com
Fixes: 32927393dc1c ("sysctl: pass kernel pointers to ->proc_handler")
Signed-off-by: Josef Bacik 
Reviewed-by: Christoph Hellwig 
Acked-by: Vlastimil Babka 
Cc: Al Viro 
Cc: Alexey Dobriyan 
CC: Matthew Wilcox 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Sasha Levin

mm: proc: Invalidate TLB after clearing soft-dirty page state

2021-03-04T10:37:45+00:00

[ Upstream commit 912efa17e5121693dfbadae29768f4144a3f9e62 ]

Since commit 0758cd830494 ("asm-generic/tlb: avoid potential double
flush"), TLB invalidation is elided in tlb_finish_mmu() if no entries
were batched via the tlb_remove_*() functions. Consequently, the
page-table modifications performed by clear_refs_write() in response to
a write to /proc//clear_refs do not perform TLB invalidation.
Although this is fine when simply aging the ptes, in the case of
clearing the "soft-dirty" state we can end up with entries where
pte_write() is false, yet a writable mapping remains in the TLB.

Fix this by avoiding the mmu_gather API altogether: managing both the
'tlb_flush_pending' flag on the 'mm_struct' and explicit TLB
invalidation for the sort-dirty path, much like mprotect() does already.

Fixes: 0758cd830494 ("asm-generic/tlb: avoid potential double flush”)
Signed-off-by: Will Deacon 
Signed-off-by: Peter Zijlstra (Intel) 
Reviewed-by: Yu Zhao 
Acked-by: Peter Zijlstra (Intel) 
Acked-by: Linus Torvalds 
Link: https://lkml.kernel.org/r/20210127235347.1402-2-will@kernel.org
Signed-off-by: Sasha Levin